When I was 19 I went on a road trip with three friends to the west coast. On the first leg of the trip we drove non-stop (save for one meal, toilets and gas) from Thunder Bay (on the border of Ontario and Minnesota) to Spokane, Washington. That was a bit heavy. I can't really sleep in cars and I ended up driving the third shift (180 km/hr across North Dakota in the middle of the night) and the last one without having slept for a couple of days. Three things stood out on that part of the trip: restaurants where every dish, even salads, contained large helpings of meat and where vinegar for chips had to be fetched from the cleaning supplies closet; interstate highways on the sides of mountains where the minimum speed limit was 70 mph; and a little town in Idaho that was between two mountains and fully underneath the highway, thus causing the sun to disappear by 2 PM. A friend got out to use the phone and the rest of us were followed by a gaggle of hollow-eyed children. Oh and the gas station in Montana that carried horse saddles and shotguns interesting.
On the way back we drove through Canada and, again, I had a late-night shift near the beginning. This time I was driving through the Rockies in an enormous thunderstorm with heavy fog. The roads were winding. The car was hydro-planing and we couldn't stop because we were in the middle of the mountains with 18-wheel logging trucks whizzing about despite the 0-visibility. Everyone else in the car fell asleep early on and no one could understand why I was so shaken afterwards. I thank Orbital for keeping my nerves calm until we made it through to Banff and the edge of the prairies. That was another non-stop trip. 30 hours - most of it spent staying 15 minutes ahead of that same storm system as it moved to the East.
Apart from all of that, it was a great trip, though I didn't really speak to my companions for several years afterwards.